If you enter
123456789123456789 in a cell in Excel, Excel changes it to
123456789123456000! Why does it do that?

You could
enter it as text to preserve all the digits, but what happens when you
try to do any math with that number-entered-as-text? Excel treats it as
if it were 123456789123456000, not
123456789123456789. Just try adding zero to it -- Excel returns
123456789123456000!

If you add 1000000000 to 0.0000000001 in Excel, Excel
returns 1000000000, not 1000000000.0000000001! Why does it do that, and what
can you do about it?

If you subtract 1000 from 1000.8 in Excel, you get 0.8.
So far, so good. But if you check whether that's equal to 0.8, Excel returns
FALSE! Why does it do that, and what can you do about it?

If you divide 1E-307 by 10, Excel returns 0.00E+00,
indicating that it considers 1E-308 (and anything smaller) to be exactly
equal to 0! Why does it do that, and what can you do about it?

If you multiply 9E+307 (or anything larger) by 10,
Excel returns the error "#NUM!"! Why does it do that, and what can you do
about it?

Here's what
you can do about it: Use xlPrecision's high-precision functions to
work
with numbers that are far too long, tiny, or huge for Excel to understand
without xlPrecision.

Excel has a few
worksheet functions to do very simple text manipulation: LEFT, RIGHT,
MID, FIND, SEARCH, REPLACE, and SUBSTITUTE. They're fine as far as
they go, but it only takes about 5 minutes to outgrow them and need
more powerful text-manipulation tools in your formulas.

inspector text adds extremely powerful worksheet
functions for manipulating and working with text in formulas, allowing you
to specify text you want to find or replace with almost unlimited
flexibility and versatility, and in extreme detail.

inspector text also adds fuzzy matching
functions to use in your worksheet formulas to determine whether the text in
two cells are similar, and exactly how similar they are, or find the
characters they have in common.

And that's not
all inspector text does. Find out more about inspector
text.